Cataract extraction with intraocular lens placement has the potential to injure the endothelium of more than 1 million patients annually in the U.S. Pseudophakic bullous keratopathy following previous cataract-IOL surgery constitutes the largest single indication for human corneal transplantation. A better understanding of the endothelial wound healing process in vivo would clearly be valuable in defining appropriate treatment modalities post cataract surgery. Although endothelial cell morphometric analysis by in vivo specular microscopy can provide relatively sensitive indices of endothelial stability, it is limited by corneal clarity, and does not work in edematous, non-transparent corneas for long periods after surgery. Therefore, detailed studies of the endothelial wound healing process in vivo have not been possible. The development of the tandem scanning confocal microscope (TSCM) has provided an innovative new paradigm for corneal research. The TSCM allows setial, high magnification, non-invasive in vivo microscopic analysis of the cornea at the cellular level. Unlike the specular microscope, the TSCM provides direct viewing of the endothlium through an edematous or cloudy cornea. Our goal is to develop the first rsliable animal model for studying and analyzing the endothelial wound healing process in vivo, and using this model, characterize the natural history of cell migration and/or proliferation during wound repair. To accomplish this, we propose to develop procedures to: 1) create an appropriate mechanical scrape woujd model, 2) use the TSCM to acquire in vivo images of the injured and surrounding endothelial area over time, 3) generate outlines of the wound area from a montage of images, and calculate in situ healing curves, and 4) quantify the dynamic morphometric changes in the endothelial cells surrounding and covering the injured region. If we are successful in establishing these techniques, future studies would examine the effect of various treatments on the endothelial wound healing response. These studies would have important and immediate, direct clinical applications to man. The PI is a recently trained biomedical engineet with experience in digital processing and analysis of real-time in vivo medical images. This project represents the PI's first in the field of vision research (applicant category b). The proposed research project will gelp the PI develop a better understanding of corneal physiology and its clinical relevance, and permit the development of a unique approach to the study of the endothelium that will provide pilot data for subsequent R01 submission and a career in vision research.